How successful are dental Implants?A personal series of 1000 implants

Mr Bill SmithConsultant Oral and

Maxillofacial Surgeon

Woodland Hospital , Kettering & Three Shires Hospital, Northampton

Method

Retrospective study Data analysed from custom database Query analysis from Microsoft Access Age Frequency of procedure Implant site Augmentation Site of augmentation Failure Analysis of failure

Demographics• Total number of implants/fixtures = 1000• Total number of patients = 490

Age Range(yrs)0

50

100

150

200

250

300

35010 to 19

20 to 29

30 to 39

40 to 49

50 to 59

60 to 69

70 to 79

80 to 89

Most implants(80%) placed between 40 to 69 years of ageNumber

Ofimplants

86% of patients are non smokers: smoking increases failure of implants both short and long term

Demographics

19951997

19992001

20032005

20072009

20112013

0

20

40

60

80

100

120

140No. of implants per year

No. of implants per year

71% of implants placed at Woodland Hospital, Kettering. 23% placed at Three Shires Hospital ,Northampton.

Implant patients

1 implan

t per p

atient

2 implan

ts per p

atient

3 implan

ts per p

atient

4 implan

ts per p

atient

5 implan

ts per p

atient

6 implan

ts per p

atient

7 implan

ts per p

atient

8+ implan

ts per p

atient

050

100150200250

No. of patients

No. of patients

50% of all patients receive 1 implant, 28% receive 2 implants.

Position of implantsUpper/Maxillary implants

0

20

40

60

80

100

120

140R molarR premolarR premolarR canineR lateral incisor2R central incisorL central incisorL lateral incisorL canineL premolarL premolarsL molar

The Incisor region is the commonest site(52%) in the maxilla(upper jaw)

totals

Position of Implants

0

5

10

15

20

25

30

35

40

45R molarR 2nd premolarR 1st premolarR canineR lateral incisorR central incisorL central incisorL lateral incisorL canineL 1st premolarL 2nd premolarL molar

Lower jaw /mandibular implants

The Molar region is the commonest site (27%) in the lower jaw c.f upper jaw

Augmentation – Bone graftsAutograft:(human to human) boneChin : N = 11Posterior mandible : N = 26Iliac crest(hip): N = 25 TOTAL Autograft = 62 patients Xenograft bone(animal to

human)Total BIO-OSS =50 patients

Total Grafts (1997 -2013)N = 113 patients

Socket augmentationN = 41

Onlay graftsN = 48

Sinus lift procedures – unilateral and bilateralN = 34

Site of Bone Augmentation

Number of graft per socket05

1015202530 R molar

R 2nd premolar

R 1st premolar

R canine

R lateral incisor

R central incisor

L central incisor

L lateral incisor

L canine

L 1st premolar

L 2nd premolar

L molar

UPPER JAW(Maxilla)

Number of grafts per socket0

2

4

6

8

10

12R molar

R 2nd premolar

R 1st premolar

R canine

R lateral incisor

R central incisor

L central incisor

L lateral incisor

L canine

L 1st premolar

L 2nd premolar

L molar

LOWER JAW(Mandible)

Bone AugmentationSummary

Patients own bone now superseded by manufactured Xenografts - BIO-OSS very successful (1% failure)

112 of 490 patients (23% patients) need an augmentation/bone graft of some typeAugmentation needed in 263 sites for 1000 implants (26% of all implants)Augmentation much more common in Upper Jaw(89%) than Lower Jaw(11%)Variety of techniques needed37% of grafts needed in mandibular molar region to maximize bone for implant so reducing risk of Inferior Dental nerve injury.

Failure of implants

15(3%) of 490 patients identified with failed implant(s)Dental Status: 11 patients are DENTATE, 4 patients edentulous.Radiotherapy to Implant site: 8 of 15 patients received radiotherapy to bone PRIOR to implant placement.20 (2%) fixtures identified as failure – complete loss13(1.3%) fixtures lost in non-irradiated cases12(80%) patients with failure identified with previous/pre-existing periodontal diseaseAll patients were non smokersAverage time from insertion to failure in 20 fixtures is 27 months(range 3 weeks to 9 years 6 months)

Implant failureFailure by site

Site Total failed fixtures

Total fixtures

Percentage failure

Upper Anterior(canine-incisor)

8 473 1.7%

Upper Posterior(premolar –molar)

6 241 2.5%

Lower Anterior(canine – incisor)

5 104 4.8%

Lower Posterior(premolar-molar)

1 182 0.5%

TOTAL 20 1000

Injury to the Inferior dental Nerve

Number of implants inserted in the lower second premolar –molar region = 132Number of Inferior dental nerves injured = 3Risk of nerve damage per implant = 3/132 =2.2%

Summary

• Upper incisor - commonest implant site• 23% of implants preceded by a bone

augmentation procedure• Bio-Oss very successful and superseeds

autografting techniques• Overall implant failure is 2% • Failure in normal/non radiotherapy cases is 1.3%• 80% of failures associated with previous or pre-

existing periodontal disease• Injury to the inferior dental nerve in posterior

mandibular implants is 2.2%